Dukkha

It is admitted that the term dukkha in the First Noble Truth contains, quite obviously, the ordinary meaning of 'suffering', but in addition it also includes deeper ideas such as 'imperfection', 'impermanence', 'emptiness', 'insubstantiality'. It is difficult therefore to find one word to embrace the whole conception of the term dukkha as the First Noble Truth, and so it is better to leave it untranslated, than to give an inadequate and wrong idea of it by conveniently translating it as 'suffering' or 'pain'.

---What the Buddha Taught, by Walpola Rahula---